Fix uninitialized strings on Windows (libusb#109)

Fix for unusual cases where the hardware does not return the name and the string is not initialized at all.

Author: JosepMaJAZ

windows/hid.c

@@ -437,20 +437,23 @@ struct hid_device_info HID_API_EXPORT * HID_API_CALL hid_enumerate(unsigned shor
 				cur_dev->path = NULL;
 
 			/* Serial Number */
+			wstr[0]= 0x0000;
 			res = HidD_GetSerialNumberString(write_handle, wstr, sizeof(wstr));
 			wstr[WSTR_LEN-1] = 0x0000;
 			if (res) {
 				cur_dev->serial_number = _wcsdup(wstr);
 			}
 
 			/* Manufacturer String */
+			wstr[0]= 0x0000;
 			res = HidD_GetManufacturerString(write_handle, wstr, sizeof(wstr));
 			wstr[WSTR_LEN-1] = 0x0000;
 			if (res) {
 				cur_dev->manufacturer_string = _wcsdup(wstr);
 			}
 
 			/* Product String */
+			wstr[0]= 0x0000;
 			res = HidD_GetProductString(write_handle, wstr, sizeof(wstr));
 			wstr[WSTR_LEN-1] = 0x0000;
 			if (res) {